Electronic polarizability in silicate glasses by comparison of experimental and theoretical optical basicities

Abstract

AbstractThe concept of optical basicity proposed by Duffy has been recognized as an extremely important issue in science and technology of glasses. In this article, the refractive index (no)‐based optical basicity Λ(no) of some binary and ternary silicate glasses was evaluated using the Lorentz–Lorenz formula, and the discrepancy between the values of Λ(no) and the theoretically calculated optical basicity Λth was analyzed to understand more deeply the electronic polarizability in binary and ternary silicate glasses. A suitable value of the optical basicity for each oxide predicting a good quantitative composition dependence of optical basicity in a given glass system was proposed. The suitable value of SiO2 for the prediction of the optical basicity of silicate glasses is Λ(SiO2 glass) = 0.53, which is larger than the value of Λ(SiO2 oxide) = 0.48 being used in the calculation of Λth so far. Other suitable values such as Λ(Al2O3 glass) = 0.62 and Λ(TiO2 glass) = 1.04 were proposed. The relationship between the optical basicity and coordination structure in some oxides in silicate glasses was discussed.